I'm building html email templates with Ink foundation. I've tested the Ink foundation basic template (http://zurb.com/ink/downloads/templates/basic.html ) on gmail, yahoo and yandex emails in ios Safari browser.
The template is shown minified, with smaller fonts. And when I'm checking not in the browser but for example on ios yahoo email app or icloud email, the email templates look right and fonts are displayed correctly.

In this image email-issues you can see the screenshots of minified look (left image) and correct view from email apps (middle image).

In Gmail it brings also the following warning message: "This message has been modified to fit your screen. Tap here to show original." and it is showing a bad modified variant (right image). And when you click to show the original, it shows the variant with minified fonts.

I'm testing the emails with Putsmail test service.

May anyone help me to understand what causes to have such issues on a well-tested email framework?